Fuel supply system



Oct. 8, 1963 Filed Nov. 16, 1956 s. G. wooDwARD ETAL 3,106,196

FUEL SUPPLY SYSTEM 3 Sheets-Sheet 1 .52 4g N0 40 Z6 57 34 P 7 4 I o f V4 46 1a 56 1- 1 A EI- 5e 44 l 52 v 50 exam 5:5: I?

[Z5 10 I6 20 ENGMIIE -16 TEMPERATURE COMPENSATDR l4 Z6 ELECTRON/c 4CONTROL.

i I r [I] 1 1| I INVENTORS STEPHEN G. Wooowmo CUR IS A. HARTMAN B 1963s. G. WOODWARD ETAL 3,

FUEL SUPPLY SYSTEM Filed Nov. 16, 1956 3 Sheets-Sheet 2 I76 i I66 /60I64 I62 I70 =-l72 2/2 155 152 FF? 4- I76 150 IN VENTOR5 ATTOEN E Y S. G.WOODWARD ETAL Oct. 8, 1963 FUEL SUPPLY SYSTEM 3 Sheets-Sheet 3 FiledNov. 16, 1956 INVENTORJ STEPHEN G. Woovwmu CURT A XH RTMAN BY m ATTORNEYUnited States Patent 3,106,196 FUEL SUPPLY SYSTEM Stephen G. Woodwardand Curtis A. Hartman, Eimira,

N.Y., assiguors to The Bendix Corporation, a corporation of DelawareFiled Nov. 16, 1956, Ser. i o. 622,618 11 Claims. (Q1. 123-li19) Thepresent invention relates generally to fuel supply systems wherein thequantity of fuel is varied by electrical means and more particularly foran acceleration control for such a system.

In some engines having such a fuel supply system when the acceleratorpedal is depressed there is produced a hesitation or fiat-spot in theresponse of the engine. In order to eliminate or reduce the hesitationof the engine to respond to an acceleration signal, an accelerationcontrol is proposed to temporarily increase the quantity of fuelsupplied by the system. To be effective such a control must respondrapidly to the accelerating signal and must accurately deliver a meteredincreased quantity of fuel over a controlled time duration.

It is accordingly an object of the invention to provide a quickresponding acceleration control of simple, reliable construction whichwill deliver a metered quantity of fuel over a controlled time duration.

Other objects and advantages will be readily apparent from the followingdetailed description taken in connection with the appended drawings inwhich:

FIGURE 1 is a schematic view of an injector embodying our invention;

FIGURE 2 is a schematic view of a portion of our acceleration control;

FIGURE 3 is a circuit diagram of the electrical control; and

FIGURE 4 is a schematic view of another embodiment of our accelerationcontrol.

Referring now to the drawings and more particularly to FIGURE 1, numeral1i) designates a source of fuel, 12 an engine with a cylinder orcombustion chamber 1-4, a spark plug .16, an intake valve 18, aninduction passage 20 and a fuel injector 22 mounted thereon. The numbersof injectors 22 conveniently corresponds with a number of combustionchambers 14 although the proportion of injectors to combustion chambersmay be increased or decreased as desired.

The injectors 22 are arranged to be actuated by an electronic control 24which is triggered by and connected to an appropriate injector 22 bytrigger-distributor 26. Unit 26 triggers or energizes the electroniccontrol 24 which remains energized for a controlled time duration. Theoutput of the control 24 is connected to an appropriate injector 22through unit 26 whereby the injector discharges fuel for the timeduration that the electronic control remains energized.

The time that electronic control 24 remains energized is regulated byvarious sensory elements including engine temperature compensator 223,altitude compensator 30, induction passage pressure responsive element32, ambient air temperature compensator 34 and low air flow control 36.

The air how to the induction passage 20 is regulated by a throttle bodyunit 38 which is provided with a pair of air flow passages 46 and 42 inwhich are respectively mounted on a shaft 44 throttle valves 46 and 48.The throttle valves are actuated by a conventional accelerator pedal 50through a link 52 and a throttle lever 54 secured to shaft 44. Atemperature control unit 56 is mounted on throttle body 38 and arrangedto position a fast idle cam 57 in the path of throttle lever 54 to pre-3,165,196 Fatented Get. 8, 1963 vent the throttle valves from fullyclosing when the control 56 is cold.

Also mounted on the throttle body unit 38 is an acceleration control 58which, as best seen in FIGURE 2, comprises a housing 60 which is securedto body 38 by appropriate bolts '62. A diaphragm 64 is marginallyclamped between said housing 60 and body 38 to separate the interior ofhousing 60 into twochambers designated respectively 66 and 68. Diaphragm64 is formed with a bleed or restricted opening 70 to provide limitedcommunication between chambers 66 and 68. An electrical contact 72 iscentrally clamped to diaphragm 64 and is urged into engagement withstationary contact 74 by means of a spring 76' located in chamber 66.Chamber 68 is connected to the induction passage 29 on the downstreamside of the throttle valves by means of conduits 78. The construction ofaccelerator control '58 is such that the electrical contacts 72 and 74are normally in engagement so as to complete a shunt circuit to bedescribed. Whenever there is a rise in the induction passage absolutepressure sufiicient to overcome the force of spring 76 the contacts 72and 74 will be moved out of en agement and the shunt circuit opened. Thecontacts 72 and 74 will remain open until the pressure in chamber 66 ascommunicated thereto from chamber 68 through bleed 70 has risen to avalue which together with the force of spring 76 is sufiicient toovercome the pressure in chamber 68. The time duration that contacts 72and 74 remain open is a function of the amount of change in pressure inthe induction passage, the size of bleed 76, the rate of spring 76 andthe relative volumes of chambers 63 and 66. The contacts 72 and 74 areadapted for connection into the circuit of FIGURE 3 which will now bedescribed.

Referring now to FIGURE 3, E designates a source of electrical energyconnected through a switch 80 and conductor 82 with a switch 84 locatedin injector-distributor unit 26. Switch 84 is mounted for actuation byshaft 86 which is adapted to be driven as a function of engine speed andwhen actuated produces -a series of pulses which are transformed bycondenser 88 and rectiher '90 into a series of negative voltage spikeswhich are eiiective to trigger a normally non-conducting transistor 92in multi-vibrator unit 94. The multi-vibrator 94 produces a pulse inconductor 96, the width of which is a function of the time constant of acircuit to be described.

In our invention alternative circuits are provided to determine the timeconstant of the multi-vibrator 94. In describing the circuitry of thetime constant in a specific embodiment a resistive-capacitivecombination is used. It is to be understood however that the circuit maybe inductive-resistive or combinations thereof and that while theresistive elements are described as variable that the inductive orcapacitive elements could equally as well be varied.

The first of the circuits includes source E, conductor 82,multi-vibrator 94 and a power amplifier 98. The time constant of thisfirst circuit is determined by condensor C and variable resistors orpotentiometers 160, 192, 104, 106 and 108 which are respectivelyvariable by altitude compensator 30, manually, induction passagepressure responsive element 32, ambient compensator 34 and enginetemperature compensator 28. The time constant in the first circuit isalso controlled by the acceleration unit 58 which provides a normallyclosed shunt path around a resistor. or impedance 110 which is connectedin series with the aforementioned variable potentiometer. The shunt pathincludes leads 112, switch 114 and lead 116. When switch 114 is closedthe acceleration control 58 has substantially no effect on the timeconstant in the firstcircu-it. However, when switch C3 114 is openresistor is effectively placed in the circuit whereby the time constantis increase The second of these circuits includes source E, conductor82, switch 84-, multi-vibrator 94- and power ampliher 93. in the secondcircuit the time constant includes condensor C, variable resistors orpotentiometers 105), 162, 118, and 168. Potentiometer 113 is manuallyvariable. A switch lid in low air flow control 36 opcratively connectedto throttle shaft 44 is adapted to alternatively select one of the twocircuits to control the time constant of the electronic control 24. Thefirst circuit is adapted to control the time constant during normaloperation and is sometimes referred to as the normal circuit. The secondcircuit is adapted to control the time constant during low air fiowconditions.

The pulse of electrical energy produced in conductor 96 by themulti-vibrator 94 has a width or time duration which is controllahe as afunction of an engine operating condition such as are introduced byvarious sensory elements into either the first or second circuit abovedescribed. The pulse or energy in conductor 96 is emplitied by theamplifier section 98 which increases the amplitude of the pulse withoutchange in width or time duration. The output from amplifier 98 isconnected through lead 122 to a conductor ring 124 formed in thedistributor portion 126 of trigger-distributor unit 26. Arm 128 securedto shaft 86 is adapted to successively connect the ring 1.4 to spacedcontact segments 13%, each of which is connected to a solenoid 132. Thesolenoids 132 are located in injectors 22 for actuation of the fuelvalve (not shown) located therein. The fuel valve and injectorconstruction is claimed and more fully disclosed in U.S. applicationSerial No. 637,852, filed February 4, 1957, now Patent No. 2,980,090,issued Apr. 18, 1961, and assigned to the assignee of the presentinvention.

in FIGURE 4 there is disclosed another embodiment of our inventionwherein the acceleration control 158 is actuated by positive pressureproduced by throttle actuated piston. As shown diagrammatically inFIGURE 4 acceleration control 153 comprises a housing 160 secured to thethrottle body 33 by appropriate bolts 162. A diaphragm 164 is marginallyclamped between the housing and throttle units and divides the interiorof the housing into two chambers designated respectively 166 and 168.The diaphragm 164 is perforated as at 170 to provide limitedcommunication between chambers 166 and 168. An electrical contact 172 iscentrally clamped to diaphragm 164 and is adapted for engagement with astationary electrical contact 174. Contacts 172 and 174 form a switchdesignated generally by numeral 214. Contact 172 is urged intoengagement with contact 174 by a spring 176 mounted in chamber 166whereby switch 214, comprising contacts 172 and 174, is normally closed.Chamber 163 is connected by means of a conduit 178 with a cylinder 130in which is reciprocably mounted a piston 182 having an operativeconnection with throttle shaft 44.

In operation when the throttle valves are open, piston 18?. travels incylinder 180 to increase the pressure in chamber 163 whereby switch 214is opened. The switch 214 will remain open until the pressures inchamber 168 and 166 through the communication of bleed 170 approach abalanced condition whereby the force of spring 176 is sufficient toagain close the switch 214. The acceleration control 153 is adapted forconnection in the circuit shown in FIGURE 3 by means of leads 212 and216 in the same manner as control 58 is connected. The operation of thecontrol 158 in the circuit of FIGURE 3 is the same as described above inconnection with the control 58.

While only two embodiments of our invention have been described it willbe readily apparent to those skilled in the art that various changes andarrangements can be made to change the objects of the invention withoutdeparting from the spirit thereof.

We claim:

1. In a fuel supply system for an internal combustion engine, anelectrically actuated fuel valve for supplying fuel to said engine, anelectrical pulse generating means operatively connected to said valvefor controlling the time duration of valve opening, impedance meansoperatively connected to said pulse generating means for controlling thetime duration of the pulses generated by said means, and a deviceoperatively connected to said impedance means for increasing saidimpedance means and said time duration of said pulses in response to achange in an engine operating condition indicative of acceleration ofthe engine.

2. in a fuel supply system for an internal combustion engine having aninduction passage and an electrically ctuated fuel valve mountedthereon, an electrical pulse generating means operatively connected tosaid valve to open said valve for the time duration of a pulse, andmeans operativcly connected to said pulse generating means andresponsive to an increase in induction passage pressure for temporarilyincreasing the time duration of said pulse.

3. An acceleration control for a fuel supply system for an internalcombustion engine having an induction passage comprising a fuel valvemounted on said induction passage, means for periodically opening saidvalve, means operatively connected to said first mentioned means forvarying the time duration that said valve remains open, and meansoperatively connected to said last mentioned means and responsive to anincrease in induction passage pressure for temporarily increasing thetime duration that said valve remains open.

4. An acceleration control for a fuel supply system for an engine havingan induction passage and an electrically actuated fuel valve mountedthereon and a circuit including impedance means having a time constantfor opening said valve for a controlled time duration comprising animpedance in said circuit and forming at least a part of said timeconstant, a switch in said circuit adapted to control the effectivenessof said impedance in said circuit to vary said time constant, and meansoperatively conneeted to said switch and responsive to an increase ininduction passage pressure for moving said switch to render saidimpedance effective to vary said time constant.

5. An acceleration control for a fuel supply system for an engine havingan induction passage and an electrically actuated fuel valve mountedthereon and a circuit including impedance means having a time constantfor opening said valve for a controlled time duration comprising animpedance in said circuit and forming at least a part of said timeconstant, a hous ng, a movable wall in said housing defining a pair ofchambers therein, means connecting one of said chambers to the inductionpassage, means defining a restricted flow path between said chambers, aswitch in said circuit adapted for actuation by said wall forcontrolling the effectiveness of the impedance of said circuit to varythe time constant therein in response to changes in induction passagepressure.

6. An acceleration control for a fuel supply system for an engine havingan induction passage and an electrical circuit including impedance meanshaving a time constant, comprising a housing, a movable wall in saidhousing separating the interior thereof into two chambers, meansconnecting one of said chambers to the induction passage, means defininga restricted flow path between said chambers, an impedance in saidcircuit forming at least part of said time constant, a shunt around saidimpedance, :1 switch in said shunt, and means connecting said switch tosaid movable wall whereby said switch is opened to vary said timeconstant upon increase in induction passage pressure.

7. An acceleration control for a fuel supply system for an engine havinga throttle and electrical circuit including impedance means having atime constant comprising a throttle actuated pressure creating means, ahousing, a movable wall in said housing separating the interior thereofinto two chambers, means connecting one of said chambers with saidpressure creating means, an impedance in said circuit forming at leastpart of said time constant and means operatively connected to saidmovable wall for controlling the efiectiveness of said impedance in saidcircuit.

8. An acceleration control for a fuel supply system for an engine havinga throttle and an electrical circuit including impedance means having atime constant comprising a throttle actuated pressure creating means, ahousing, a movable Wall in said housing separating the interior thereofinto two chamber, means connecting one of said chambers with saidpressure creating means, means defining a restricted flow path betweensaid chambers, an impedance in said circuit forming at least part ofsaid time constant, a switch movable by said wall to one positionwherein said impedance is shunted in said circuit and to anotherposition where said impedance is effective to vary said time constant,and resilient means in said housing urging said switch toward said oneposition.

9. In a fuel injection system for a combustion device of the typeincluding injection valve means to supply a fuel under pressure to saiddevice, control means comprising actuating means adapted to open saidvalve means by and for the duration of an electric current pulse appliedthereto, monostable pulse forming means comprising a first amplifier, asecond amplifier, load resistance means for each said amplifiers, directcoupling means between the output of said first amplifier and the inputof said second amplifier, a resistance-capacity coupling network betweenthe output of said second amplifier and the input of said firstamplifier, to normally pass an output current through said firstamplifier and to normally bias said second amplifier to output currentcut-off, whereby to render said first amplifier temporarilynon-conductive during a period determined by the time constant of saidnetwork upon the application of a triggering pulse to said secondamplifier, to produce output current pulses of said first amplifier,means to energize said actuating means by said output current pulses,and further means to vary the time constant of said network, whereby tocontrol the fuel injection time of said valve means.

10. In a fuel injection system as claimed in claim 9, including means tocontrol said last-mentioned means in dependence upon at least onevarying operating condition of said device affecting the fuel-air ratioin the combustion chamber thereof, to substantially maintain the fuelairratio of a predetermined value.

11. In a fuel injection system as claimed in claim 9 for use in theinternal combustion engine of an automotive vehicle, includingtriggering pulse generating means for said second amplifier synchronizedwith said engine, and means to control the resistance of said network independence upon at least one operating condition of said engineaffecting the fuel-air ratio in the combustion chamber thereof, wherebyto substantially maintain said fuel-air ratio at a constant value withina predetermined range of variation of the engine operating conditions.

References Cited in the file of this patent UNITED STATES PATENTS2,482,254 Fairchild Sept. 20, 1949 2,521,244 Moore Sept. 5, 19502,859,738 Campbell Nov. 11, 1958 2,911,966 Pribble Nov. 10, 19592,967,953 Pribble Jan. 10, 1961

1. IN A FUEL SUPPLY SYSTEM FOR AN INTERNAL COMBUSTION ENGINE, ANELECTRICALLY ACTUATED FUEL VALVE FOR SUPPLYING FUEL TO SAID ENGINE, ANELECTRICAL PULSE GENERATING MEANS OPERATIVELY CONNECTED TO SAID VALVEFOR CONTROLLING THE TIME DURATION OF VALVE OPENING, IMPEDANCE MEANSOPERTIVELY CONNECTED TO SAID PULSE GENERATING MEANS FOR CONTROLLING THETIME DURATION OF THE PULSES GENERATED BY SAID MEANS, AND A DEVICEOPERATIVELY CONNECTED TO SAID IMPEDANCE MEANS FOR INCREASING SAIDIMPEDANCE MEANS AND SAID TIME DURATION OF SAID PULSES IN RESPONSE TO ACHANGE IN AN ENGINE OPERATING CONDITION INDICATIVE OF ACCELERATION OFTHE ENGINE.